Photographic receiving apparatus



0,. A. CULVER.

PHOTOGRAPHIC RECEIVING APPARATUS. APPLICATION FILED JUNE 19. 1919.

v \u 0 NH ATTORNEY UNETED STATES PATENT OFFICE.

CHARLES A. CUL'VER, OF BELOIT, WISCONSIN.

PHOTOGRAPHIG RECEIVING APPARATUS.

Specification of Letters Patent. P t t 14, 1

Application filed June .19, 1919. Serial 110. 305,420.

Improvements in Photographic Receiving Apparatus, of which the following is a specification.

This invention relates to a new and improved means for recording signals.

The invention is particularly directed to means constructed in co-action with oscillation receiving systems, for recording indications corresponding to the received signals.

In the more preferred formsof my invention, the signals are recorded on a chemically-sensitive strip by the use of light waves controlled by oscillation-responsive means comprisin an electrical coil in electromagnetic relation with a Vib'ratable element and a mirror controlled by the vibratable element for controlling the character of light waves impinging on the sensitive strip. Means are provided for regulating the frequency or period of vibration of the vibratable element, in coaction with means for tuning the antenna circuit relative to the vibratable element, thereby weeding out the reception of any undesired waves. The-recording mechanism is preferably arranged to automatically effect the recording of the signals, as by lmparting uniform or other predetermined rate of travel to the sensitive strip under controlled shutter exposure, and automatically developing and fixing the successively subjected portions of the strip.

Further features and objects of the invention will be more fully understood from the following description and the accompanying drawing, in which,

Fig. 1 is a diagrammatic view showing one form of the invention;

Fig. 2 is a diagram of a radio receiving system for receiving dam ed waves and embodying the form of my invention shown in Fi 1- Fig. 3 is a diagram showing the form of my invention of Fig. 1 embodied in a radio receiving system adapted to receive undamped waves; and v Fig. 4 is a detail top plan view of the clamp for adjusting the effective length of the reed.

Referring to Fig. 1, the coil 1 isdisposed in suitable relation with the pole 2 of the permanent magnet 3, the terminals 4 and 5 of the winding of the coil 1 being suitably connected with the receiving circuit, as more particularly described hereinafter.

The magnet 3 is suitably supported in fixed relation, as by means of the bracket 6 having base 7 adapted to be secured to any suitable fixed support. As shown, the magnet 3 may be mounted with its poles one vertically above the other.

In suitable vibratory relation with the magnet 3 is arranged the reed 8 which is preferably of a free-reed type, as by mount ing its upperend 9 in determined, relatively fixed relation to provide its free end 11 to extend normally relatively closely adjacent to the pole 2 of the magnet 3.

The reed 8 controls the mirror 12, or other suitable light diverting means; as shown, such mirror 12 is preferably suspended from the reed 8 by means of a strip 13, of rela; tively highly flexible material. The mirror 12 is large in mass, i. e., of high inertia, relative to the force required to flex the flexible stri 13.

he reed 8 is preferably of very thin,

highly resilient, material to provide a very low damping factor and may be of magnetic material, or may have its portion 11 adjacent the pole 2 of the magnet 3 of magnetic material, or equivalent, as is understood; or-the reed 8 may be of non-magnetic material and a suitable facing or insert of magnetic material provided in adjacent magnetic relation with the pole 2 of the magnet 3.

In co-action with the mirror 12 is provided a source of light 14, of any approved type, and arranged to direct the incident .rays of light 15 on the mirror 12, and, if desired, the lens 16' arranged to concentrate such incident rays of light 15 on the mirror 12. The reflected rays 17 are refracted through the lens 16 onto the strip of sensitive paper 18. The lens 16 may be of the double convex form, and the cylindrical object lens 19 may be employed in co-action therewith to locate the focus of the reflected rays17 substantially withinthe plane of the face of the sensitive paper 18.

' Upon the reception of oscillations in the antenna circuit, and the consequent excitation of electrical impulses through the coil 1 the reed 8 is electro-mechanically vibrated in correspondence with the electrical'excitations, and by reason of the low damping factor of the reed 8, the relatively high flexibility of the strip 13 and the high inertia of the mirror 12, the mirror 12 is deflected rotatively, thereby deflecting correspondingly the deflected rays 17. In the particular a-rrangement shown in the drawings, the exsystem is adapted tent of arcuate deflection of the reflected rays 17 is approximately twice the arc of oscillation of the mirror 12. V

The sensitive strip. 18 is suitably mounted qn rolls 20, 21, suitably driven by clockmechanism (not shown), or equivalent, to provide a substantially uniform travel of the strip 18, say, in the direction of the arrow 22, the whole being enclosed in a suitable light-proof container, having a suitable light receiving opening in which is disposed the lens 19.

. I. have discovered that the extent of defiection 011' the deflected rays is commensurate with the amount of energy of the transmitted waves, the duration of deflection corresponding to the duration of the wavesof the particular frequency to which the reed is tuned.

Upon adjustment of the effective length of the reed 8, its period of vibration is correspondingly modified whereby the frequency of the impulse sensitive-device comprising the codl 1., magnet 3, and reed 8 is accordingly regulated. As one form of adjusting the length of the reed 8, I have shown the inner clamping plate 23, the outer clamping plate 24, and clamping screws 25, 25, tapped into the pole 10 of the magnet 3, said inner clamping plate being cut awa at 26 to receive the correspondlngly thickened lip 27 of the reed 8, as indicated in Figs. 1 and 4. y

In Fig. 2, I have indicated a suitable form of radio receiving system including a vacu-' um valve detector, embodying my photographic recording device, the same being arranged for receiving damped waves of a predetermined frequency. Such receiving for the reception of signaling oscillations emitted by a spark transmitter. In the diagrammatic view of Fig.2, the antenna is indicated at 30, and connected through the closed tuning circuit comprising the primary coil 31 and adjustable condenser 32 and with the ground 33. The secondary coil34, in inductive relation with the primary coil 31, is connected through its one terminal through the condenser 35 and high resistance 43 withthe grid electrode 36 of the vacuum valve detector 37. The filament cathode 38, heated by the battery 39, is connected through its one terminal with the other terminal of the secondary coil 34, adjustable condenser 40 bridging across the terminals of the secondary coil 34. The anode plate 41, of the vacuum valve detector 37, is connected through the battery 42 with the terminal 5 of the excitation coil 1, the

terminal 4 of the excitation coil 1 being counected with the remaining terminal of the cathode filament 38.

The reed of the photo aphic recording device indicated at 8, the l e iis at 16, and the sensitive photographic film 18 corre 0nd to like parts referred to more particu arly hereinabove.

In the receiving system shown in Fig. -3, I have indicated device 1 suitably connected in suitable form of receiving system including a vacuum valve detector 37, arranged for the reception of undamped oscillations of a predetermined frequency, like elements of the receiving circuit of Fig. 3 being designated by like reference characters, as 1n Fig. 2, the connections being modified, however, to include the inductance 45 connected to one terminal of the secondary coil 34, the other my photographic receiving terminal of the inductance 45 being connected with the terminal 4 of the oscillation responsive coil 1, and the variable condenser 46 bridging the battery 42 a-nd'the oscillation responsive coil 1. I a

In such receiving circuits, the vacuum valve is arranged to generate high frequency oscillations, the frequency of which is controlled by the variable elements of the circuit, as will be understood. The oscillations of the local circuit of the oscillation sensitive coil 1 react with the oscillations set up in the antenna 30 to produce in such local circuit the beat tone, which is rectified by elements of the receiving circuit.

A dot and dash record is indicated in Fig.

1, on an enlarged scale, and in Figs. 2 and 3, on a reduced scale. During the intervals of quiescence the beams of reflected raysv 17 efl'ect theimpression on the traveling sensitive strip 18 of a substantially rectilinear line indicated at 50-50, corresponding to an axis of abscissa and upon the reception of a dot, representing a relatively small interval of excitation, a relatively thin impression is developed on the sensitive strip 18, as indicated at 51, 52, 53, etc; whereas upon the reception of a dash representing a relatively long period Oif excitation, a relatively thicker impression is' developed on the trav- The beat tone frequency is then adjusted to the reed frequency adjusting the variable tages of photographic records generally.

I have discovered that reeds of the free-- eling sensitive strip 18, as is indicated at 54, 55, 56,

The developed photographic record represents, accordingly, a sequence of relatively thin and relatively thick impremions extending in the direction of length of the strip,

reversely to the direction of travel of the strip, thus enablingthe operator to readily read or receive the message. The record is permanent inform and possesses the advancillations. I

, Whereas, I havedescribed my invention by reference tospecific forms thereof, it will be understood that many changes and modifications may be made without departing from the appended claims.

. I claim;

1. The combination with electrical oscillation means, of an electro-mechanical vibratableelement of the spring type controlled by said means, the natural stifi'ness of the spring 'b'ein sufficiently low to give substantially simp e-harmonic vibration for small displacements when loaded, means forvarying the "fre uency of said element, and loading meansor'recording the vibrations of said vibratable, element."

2. The combination with a selective electrical oscillation receivin means, of a selective electro-mechanical vi ratable element of the spring type controlled thereby, the natural stiffness of the s ring being sufiiciently low to give substantia 1y simple harmonic vibrations for small displacements when load ed, means for varying the frequency of said element, and loading means for recording the vibrations of said vibratable element.

3. The combination with oscillation receiving means, of a reed electro-mechanically controlled by said receivin means, means for mounting said reed sole y at one end, a relatively short, highly flexible elementsecured, to the free end of said reed and a mirror of relatively high inertia carried by said flexible element.

4. The combination with oscillation receiving means, of vibratable means of the spring type responsive to the oscillations of the receiving means, andloading means to indicate the vibrations of the vibratable means and possessing greater inertia than the vibratable means.

5. The combination with oscillation receiving means, of vibratable means of the spring type responsive to the. oscillations of the receivin means, means for varying the frequency 0 the vibratable means, and loading means to indicate the vibrations of the vi ratable means, said vibratable means having les inertia than the loading means.

6. The combination with oscillation receiving means, of vibratable means responsive to the oscillations of the receiving means, a vibratable light-reflecting member connected with the said vibratable means for actuation thereby and possessing greater inertia than the vibratable means, and lightsensitive means adapted to record vibrations of the light-reflecting member.

i 7. In combination with an electrical oscillation receiving circuit, .a leaf spring means of low inertia and high relative displacement for a given applied force, a recording means mounted on and having an inertia higher than the said leaf spring means,and further means to give a series of mechanical impulses to said spring means by virtue of the electrical oscillations in said receiving circuit.

In testimony whereof I afiix my si ature.

CHARLES A. CUL ER. 

